all equipment and tools deleted due to bug/useless feature

i had just beat the wither in the end and wanted to safeley go back because sometimes if i got through the portal in auto-kills me and deletes my items, which is another bug but not the one i want to talk about. So i wanted to keep all my netherite armor and stuff safe so i put it in a shulker box located ontop of the obsidian you spawn on in the end. My plan was to come back to the end after, put down an ender chest then transfer my items into there. This did not happen as when i when back into the the end with the chest the shulker box was deleted. I assume this is to stop from suffocating but why replace all of the surrounding area when you only spawn in the middle? I spent months getting all of those tools and armor and now i have to do it all again.